Tool holder adapted for motor driven striking tools



April 12, 1932. E. G..HYSING ET AL. 1,853,123

TOOL HOLDER ADAPTED FOR MOTOR DRIVEN STRIKI NG' TOOLS Filed Feb. 16 Q 1951 Patented Apr. 12, 1932. i

JOHAN ADOLF JOHNSON, OF BlOGKHOIM, SWEDEN nan: eosrar EYSING AND KARL.

PATENT OFFICE TOOLHOLDER ADAPTED FOB MOTOR DRIVEN S'IBIKDTG TOOLS Application filed February 16, 1931, Serial No. 516,110, and in Sweden February 8, 1880.

. tor-driven striking tools, in which the'ver working tool, for instance a borer, a punc or the like, is inserted into the holder. In such holders it easily happens that the tool, for instance the borer, is thrown out away from the holder when the fore end of the borer comes out at the opposite side of the wall or the like to be pierced.

' According to the present invention this inconvenience is avoided by the fact that a portion of the tool-holder is made of a resilient matter, for instance rubber, and that a channel arranged in this portion in order to allow.

the tool to be pushed into the holder, is given a cross-section similar to, but less than the cross-section of the tool shaft. When the tool is pressed into the holder, that portion of the holder which is made of resilient matter will, thus, entirely by its own elasticit press against the tool shaft and hold or loo this by friction. The annexed drawings show an embodiment of the invention, applied to a holder for locking a borer having a shaft crossshaped in section. Fig. 1 shows the striking tool as a whole, in side view, and Fig. 2 is a detail of the holder partly in longitudinal section and having 1 a borer inserted therein. I Fig. 3 is a section on the line III,III and Fig. 4 is a section on the line IVIV in Fig. 2.

Referring to Fig. 1, 1 is the frame of the striking tool, containing an electric motor 2 which rotates a sleeve 3. Mounted to slide in this sleeve 3 is a striking body 4 receiving a reciprocating motion by the action partly of the shock of the striking body 4 against the anvil 5, partly by an energy storer or the like, for instance ,balls 6 acted upon by the centrifugal force. Inserted into the anvil 5 is a tool-holder 7, the, downward motion of the same being limited by the bows 8 mounted at the bottom-end of the frame, the outer ing on this occasion simultaneously a ainst any support, the holder has its fore en provided with a sleeve 11 otrubber or similar resilient matter pushed on the flange 10. The channel made in this sleeve 11 to allow the borer '12 to be inserted into the holder is, 2.0- cording to the present invention, given a cross-section similar to, but somewhat less than the cross-section, of the shaft of the borer. By this fact the borer is rigidly se- I cured in the sleeve by friction caused by the sleeve pressing by its own elasticity against the tool shaft.

The invention may be applied to all sha of cross-sections of the tool or tool-shaft, or instance a circular or a s ua're one. The shape of cross-section of t etool or toolshaft shown in the drawings is only an embodiment. The manner in which the resilient portion of the holder is fixed to the other" part of the holder may, of course, also be varied in many ways without departing from the principle of the invention.

Having now particularly described the nature ofpur invention and the manner of its operation, what we claim is Tool holder for motor-driven striking tools, comprising a main tool holder member, provided with a flange at its forward end, an additional holder member made of a resilient material, this additional member being provided at its rear end with a fian corresponding to the flan e of the main holdor member and adapted or fixing the resili-v ent part to the forward end of the main tool holder; the main tool holder and the resilient member each being provided with a channel with a constant cross section, which concerning the main tool holder is of thesame size as the cross section of the tool shaft but 5 concernin the resilient member is somewhat less than e said cross-section, whereb when the tool shaft is pushed into the tool older, the resilient member holds the said shaft in its position by friction arisingl from forces at right angles against e axis of the In testimony whereof we aflix our signatures.

ERIK GUSTAF HYSING.

mu. JOBAN 'ADOLF JOHANSON. 

